Grinding machine



Aug. 28, 1928.

E. M. TAYLOR GRINDING IAC-HINE Filed Jan. 25, 1926 6 Shuts-Shut 1 J Q/03 no v 6 I f a 7 I a? a; EOE-77" Aug. 28, 1928. 1,682,673

. E. M. TAYLOR GRINDING ucnxua Filed Jan. 25. 1926 e'slmtatshuz 5,77ZmErz 0 1' if/Mara .1 1. 75/10/- Aug. 28, 1928.

E. M. TAYLOR GRINDING CHINE Filed Jan. 25. .1926 v 6 Shoots-Slug 427ZUE777L m Jam y Aug. 28, 1928.

1,682,673 E. M. TAYLOR GRINDING MACHINE Filed Jan. 25, 1926 5Shanta-Smut 5 9 i Q A N r" q a r h h m n?) 2 Q "N Aug? 28, 1928.1,682,673

- E. M. TAYLOR GRINDING IACHINE [HI/677 7'07 Edward /7- Ta 60/- yg gPatented Aug. 28, 1928.

umreo STATES PATENT OFFICE.

EDWARD M. TAYLOR, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO THE HEALDMACHINE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF IA8-SACHUSZETTS.

GRINDING MACHINE.

Application filed January 25, 1926. Serial No. 83,592.

The invention relates to grinding machines, particularly those adaptedto autonyttically reduce successive workpieces to a given finished size,and the invention pro- U vides means to compensate such machines for thewear on the grinding wheel and for the reduction of said wheel bydressing and truing operations. Such compensation operates in connectionwith the cross-feed mechanism of the grinding machine, which proressively advances the grinding wheel or the workpiece to cause theformer to cut the latter. The invention herein set forth is animprovement on that shown and described in the copending application of\Valdo J. Guild, Serial No. 48,734, filed August 7, 1925.

The present improvement eliminates many of the pawl and ratchet devicesemployed as 90 compensatory means in Said Guild machine,

and substitutes therefor a means of compensation, for wheel wear andremoval of wheel matcrial, ,..hy dressing, which practically eliminatesall. possible sources of machine 5 and human error. In particular, thepresent invention provides a wholly automatic compensatin mechanism, inplace of compensatmg mechanism actuated by manual movement of a handwheel in the Guild machine. Thus the present mechanism preventsaccldcntal double or triple compensation, whic resulted when theoperator unintentiona ly went through certain motions more than once.

In the drawings, Fig. 1 is a plan view of a grinding machine embodyingthe invention.

Fig. 2 is a vertical sectional view of the cross-feed mechanism taken onthe axis of the feed screw shaft.

Fig. 3 is a horizontal section of the same parts.

Fig. 4 is a fragmentary elevation on an enlarged scale. looking from theright hand 4.5 side of Fig. 1. 0

Fig. 5 is a plan view of the parts shown in Figs. 2, 3 and 4.

Fig. 6 is a front elevation of these parts. Fig. 7 is a fragmentaryview, taken on the 60 section line 7-7 of Fig. 4, through a certainshaft.

Fig. 8 is a front elevation of the grinding machine, showing the tableactuating mechamsm.

F 9 is a Wiring diagram for the machine. Fig. 10 is an elevation of themechanism shown in Fig. 6, with the hand wheel removed.

Like reterence characters refer to like parts in the difierent figures.Referring first to Fig. 1, an internal grindlng machine is shown havinga reciprocatory table or carriage 1 such as is ordinarily pr0- vided inany internal grinding machine. In

such a machine, either the grinding wheel or the work to be ground maybe carried on the table 1, the reciprocation of the latter beingutilized in either case to produce a relative traversing movementbetween the grinding wheel and the work. As here shown, the table 1supports and carries a wheel head 2, while the work which is to beoperated upon is held in a work head 3, the latter being carried by abridge 41, which spans the slideways provided by the machine frame forthe back and forth movement, of the table 1.

The grinding wheel 5 is carried on a spindle 6 which 1s suitablyjournalled in the wheel head 2, and any suitable means,.which need notherein be described, is provided to rotate said spindle 6 and wheel 5.The workpiece 7, which is held by a suitable chuck 8, carried b the workhead 3, is also rotated, but desirably at a slower speed.

The reciprocation of the table 1 to cause the rotating grinding wheel 5to make the required interior traverse of the rotatin workpiece 7 may beimparted in any wel known manner, as for instance by the use of thefluid pressure controllin and reversing mechanism described in UnitedStates Letters Patent No. 1,582,468, to Heald and Guild, granted April27 1926. Such mechanism is now well-known in grinding machines andrequires no detailed description; it is sufficient to note for presentpurposes, that the driving means employed for the reciprocation of thetable 1, be it hydraulic drive, or gear drive, or any other type,procures thelreversal of said table at each end of the latters normalworkin stroke by the use of spaced adjustable dogs%6 and 77, carried bythe table 1 and adapted to alternately engage and move a reversingmember 78;

said member 78, during the grinding operation, when the wheel 5 ismoving back and forth within the workpiece 7, is situated between thetwo dogs 76 and 77 in position to be struck alternately by said dogs,and said member 78, by its "consequent movements, first in one way andthen the other, effects the reversals in the travel of the table 1.

In this embodiment of the invention the wheel head 2 is carried by across slide 2 which is mounted on ways on the table 1. Referrin now toFig. 2, a transverse feeding element tor said cross slide, here shown asa screw shaft, is indicated by the numeral 10.

Rotation of this shaft in a clockwise direction (in this particularembodiment of the invention) is adapted to advance the grinding wheel 5in cutting relation to the workpiece'7. Said screw shaft is adapted to'be rotated manually by means of a hand wheel 11 and mechanically from aratchet wheel 12, the latter being automatically given a step-by-stepmovement, as will hereinafter appear. Ratchet wheel 12 is directlyfastened to an annular piece 11, which is herein shown as formedintegral with the hand wheel 11. Fastened to the piece 11 is a stud 13,which 'rotatably carries a pair of gears 14 and 15, formed out of asingle piece.

Keyed, or otherwise fastened to the shaft 10 is a sleeve 16. This sleeveprovides a convenient bearin for the annular piece 11, and it also provies a gear portion 16 which meshes with the gear 14. Another sleeve 17surrounds the shaft 10, but is not fastened thereto. This sleeve 17'hasa gear portion 17 which meshes with the gear 15.,

Considering, for the moment, that the sleeve 17 is stationary,,it willbe apparent that rotation of the elements 11, 11, and 12, will causerotation of the screwshaft 10, but at ve much reduced speed, since theears 14 an differ slightly, and only slightly, indiameter. I

Referring now to all the figures, exce t Figs. 1 and 7, a ring 18 iscarried by the e ement 11. This ring'18 desirably has suit able scalemarkin s on it, as shown in Figs. 4 and 5. Prefera ly this ring isadjustable on the member 11, and to this end the internal front edgeisbevelled, as shown in Figs. 2 and 3, and a bindin screw 19 holds it inany desired position of adjustment. On the ring 18 is a cam projection20. A air of contact terminals is shown in section in Fi 2; the machineprovides another pair which are identical in construction, so one descrition will serve for both. As shown, thum screws 21 and 22 are carried byrock levers 23,v ivoted at 24. Terminals 25 are carried by t e levers23, and when the cam 20, by engagementwith the screw 21 or 22 moves arock lever upwardly, the terminal in question, 25, engages a terminal26. The latter are mounted on the front of plungers 27,

which are slidably held by cylindrical members 28 of insulatingmaterial. The plungers have reduced portions-"29 which extend throughthe insulating material and are threaded at the rear end. Springs 30 fitaround the reduced portions 29. The threaded parts of the portions 29serve as binding posts, nuts 31, 31 bein provided for the attachment ofwires an at the same time to allow the plungers 27 to be pressed into agiven position by the springs 30. The above construction allows a firmcontact to be made, using heavy rock levers 23 for accuracy, yet withoutdanger of breaking any arts.

Referring now to Fig. 6, a stationary art of the machine carries a cambar 32, an on said bar is an adjustable cam member 33. The latter isenga ed at each normal working reciprocation of t e table 1, by a roller34, thus raising the latter. Said roller 34 is carried by a member 35which is pivotally mounted at 36. A stop lo 37 holds the parts in theposition of Fig. 6, t is being the mactive position. A pawl 38 on member35 is adapted to engage and move the ratchet 12, sai pawl having aspring pressed plunger 39 engaging a cut out portion 40 in the -stud 41on which said pawl is pivotally mounted, whereby the pawl tends to movein a clockwise direction to engage said ratchet 12. Normally, however,the pawl 38 is clear of the ratchet12, the position of which in Fig. 6is clearly indicated. Consequently the cross-feed mechanism can bemanually adjusted backwards or forwards at any time, except when the cam33 is en aging the roller 34, by movin the hand whee 11. The means tonormally old the pawl 38 clear of the ratchet 12 is shown as anirregular surface 42 on said pawl 38 which engages a shield pin 43 atthe end of a lever 44 pivoted at 45, said lever having an adjustingscrew 46 engaging a stationary lug 47.

This automatic step-b -step movement of ratchet 12 in response tot eactuation of pawl 38 induced by the reciprocation of table 1 moves theannular member 11 and conse 'i' a quently also the rin 18 and the camprojcc tion 20. The thum screws 21 and 22 are in the path of the camprojection 20 and consequently movement 0 the latter successively causescontact, first of terminals 25 and 26, when the screw 21 is actuated,and subsequently of terminals 25 and 26. tion between the two sets ofsimilar contact mechanism described in a single descri tion above, seeFig. 6 and also the diagram 0 Fig. 9 which shows the operative relation(not the construction) of the parts. When the terminals 25 and 26 makecontact, an electrical circuit is closed which, by the mechanismpresently to be described, causes the table 1 to have an amplifiedstroke to the right, in order to withdraw the grinding wheel 5 from thework, and simultaneously causes a wheel For the rela lib . nector 85,which grinding wheel or the dressing member or diamond 9 to move intothe amplified path of said grinding Wheel, thereby to true the peripheryof the atter as it passes the oint of said diamond.

As shown y the wiring diagram of Fig. 9, electrical current may besupplied by a generator G driven continuously by any suitable means, notshown, from the same source of power that is used work spindle. Oneterminal of this generator G is grounded, as shown at 79, and the otheris connected by a supply wire 80 to the central bar or plate 81 of a twoway switch,-the latter being designated as a whole by the numeral 82 andbein disposed, as shown in Fi 8, on the front the machine. Said switc i82 provides additional contact plates or bars '83 and 84 arranged onopposite sides of the central bar 81 and adapted to be alternatelyconnected electrically to said central bar 81 by a conis mounted on anoscillatory member 86. The latter is pivoted at 87 and in its normalposition, as shown in Fig. 9, disposes the connector 85 in contact withand across the two plates 81 and 83; in the other position of movablemember 86 the connector 85 connects the two plates 81 and 84.

When the grinding wheel is taking the preliminaiy cutson a workpiece 7,as illustrated in ig. 1, the oscillatory switch meniber 86 occupies saidnormal position of Fig.

, within t e workpiece,

together as above connected by a wire 9, and under these'conditions thesupply wire from the generator G is connected to a wire 88 running fromthe plate or bar 83 of the switch 82. Said wire 88 runs to the 'coil' ofan electromagnet 89 disposed in the 15131 of the machine, as shown in F15. 8 an A return wire 90 from the coil 0 the electromagnet89 isconnected to a finger 91 provided onany convenient stationary portion ofthe machine frame. A contact plate 92 is carried b the table 1, andduring'th'e normal workin traverse of the table 1, when the grindinwheel 5 is moving back and forth the finger 91 is in contact with thecontact plate 92. The latter is minal 26.

When the terminals 25 and 26 are brought 1 and forth within theworkpiece, the block 106 of dog cam 20, the circuit throughelectromagnet 89' is completed, since the terminal 25 s grounded, asshown at 94, Fig. electromagnet 89, causing attraction of an armaturemember 95, and the consequent elevation of its attached lever arm 96,these parts being pivoted at 97 on the front of the machine. Suchmovement of the lever arm 96, responsive to the engagement of can 20with screw 21, is made use of to automatically interrupt the grindingoperation on the workpiece 7 for the dressing and truing of the indingwheel 5, in advance of the final and ishing cuts taken for the rotationof the arm 96 93 to the contact terdescribed, by the action 0 9. Thisenergizes the.

by said wheel to bring.

the workpiece to the desired size. This involves the withdrawal of thegrinding wheel 5 from the workpiece, and the disposal, in thetemporarily amplified path of movement of said wheel of the dressingdevice or diamond 9; these two operations are efiected through themedium of the lever arm 96 in the follow mg manner As fully described,in the copending application of Heald and Guild, Serial No. 25,900,filed April 25, 1925, the dressing device 9 may be moved into operativeposition through the medium of fluid under pressure, more especiall whensuch fluid under pressure is employs for imparting reciprocation to thetable 1. For the disclosure of the present invention it is suflicient tonote that the dresser point 9, see Fi s. 1 and 8) suitably mounted on ana justab e screw plug 98, is lowered into operative position by thedownward swinging movement of a carrying member 69, which turns on atrunnion 99 provided by a suitable standard 100 rising from thestationary frame of the machine. When the lever is moved, a downwardextension 101 thereof communicates said movement to a valve 102, Fig. 8,thus making the pressure fluid active, through the medium of piping 103(Fig. 1) against a piston, not shown Movement of said piston iscommunicated to a lever 104 which is connected to the carrying member 69by means of a link 105, and thus actuation of valve 102 in response toenergizat-ion ofelectromagnet 89, results in movemer t of the dresserpoint 9 to its dressing position in the path of the wheel 5.

As before stated, the other operation in-.

left hand table dog 77, which limits the right hand movement of table 1,is carried by a block 106, which, instead of being secured directly tothe table 1, as is the case with the block 107 of dog 76, is mounted soas to be capable of sliding freely longitudinally of said table. Undernormal conditions, when the table is making its usual workingreciprocations to traverse the grinding wheel 5 back 77 is held indefinite'spaced relation to a b ock 108, which latter, the same as theblock 107 of right handdog 76, is a stationary block adaptedto maintainits predetermined setting or adjustment longitudinally of the table 1,as given it by any'suitable ad ustment or holding devices, hand screwnuts .109, 109, applied to both blocks 107 and 108 and engaging with thescrew rack 110 on the table 1.

The device employed to hold the slidable block 106 in spaced relation tothe fixed block 108 is here shown as'a latch lever 111 pivoted at 112 onblock 108, and having its free end such for instance as the disposed bygravity in abutting relation to a shoulder 113 on block 106, therebyholding the block 106 at a predetermined distance to the right of block108. \Vhcn the latch member111 is lifted to free its end from theshoulder 113, the normal connection between the slidable block 106 andthe fixed block 108 is broken, and when this occurs on the right handmovement of table 1, the dog 77 will bear without effect against themember 78. Thus the right hand movement of the table 1 on thisparticular stroke will be extended be- 'yond the usual reciprocatoryworking path, and the grinding wheel 5 will be carried out of the holein the workpiece to a point just beyond that occupied by the dressingdevice 9, which latter, as already described, has been moved intooperative position as the right hand travel of table 1 begins.

This amplified travel of table 1 involves relative sliding movementbetween said table and the block 106. owing to the obstruction which thereversing member '78 imposes against the dog 77 to prevent the block 106from moving with the table: finally the block 106 brings up against theblock 108, whereupon the solid backing thus atlorded for the block 106enables the dog 77 to shift the member 78. This procurcs reversal of thetable 1, and the left hand movement of said table thus inaugurated iscaused to restore the parts automatically to normal position in thefollowing manner A member 114 pivotally mounted on the frame of themachine has a pair of inclined surfaces for cooperation with inclinedsurfaces 115 and 116 at the lower corners of the block 106. A spring 117presses said member 111 upwardly. In the normal grinding operation ofthe machine when the blocks 106 and 108 are connected by latch 111, theinclined surfaces on member 114, although in the path of block 106,offer no struction to the back and forth travel of said block in unisonwith the table 1, it being obvious that when either lower corner of theblock under these conditions strikes either of said bevelled surfaces,such contact will wedge the spring 117 downwardly, said spring yieldingsufficiently to allow the block 106 to pass over the member 114.However, when the block 106 has been freed from the block 108 abovedescribed, to amplify a single right hand stroke of the table 1, theensuing reversal of said table, with the block 106 still free. finds theright hand surface of member 114 in position to contact with thebevelled corner 115 of said block, and under these conditions, theobstruction offered is suflicient to overcome whatever friction theremay be tending to cause the block 106 to move to the left with thetable. The block 106 being thus held stationary while the table 1 andblock 108 continue to move to the left, the latch member 111 finallyresumes its effective obnormal position relative to the block 106, theend of said latch member dropping behind the shoulder 113, and the partsbeing thus automatically restored to normal position at the conclusionof each single amplified reciprocation of the table 1.

Said single amplified reciprocation of the table 1 for wheel dressingpurposes is inaugurated automatically when preliminary grinding has beencarried to a predetermined point in relation to finished size on eachworkpiece, by the makin of electrical con tact through the terminai 25and 26, as already described, thus moving the lever 96 about its pivot97. The lever 96 has a roller 118 on the upper portion thereof, and uponmovement of this lever during normal working traverse of the grindingwheel 5, the roller 118 engages and lifts the latch lever 111. thuscausing the above described amplified movement of the table 1, whichcarries the grinding wheel 5 to the right, past the diamond 9, and thento the left, again passing said diamond before resuming the normalreciproeatory traverse of the workpiece 7. Thereupon, by any suitablemeans, such as by the engagement of a cam member 119, fastened to thetable 1 (shown in Fig. 1) with a roller, not shown, on a forwardextension of lever 104, the diamond 9 is rocked upwardly into theinoperative position that it normally occu ies.

On this amp ified right hand dressing stroke of the table 1, an arm 120,Fig. 8, pivoted at 112 and hanging by gravity in the position shown inFig. 8, strikes an arm 121 of movable switch member 86, thereb rockingthe connector of said switch member away from bar 83 (see Fig. 9), whichprevents a repetition of the dressing stroke. Thereupon the connector 85is disposed in position to connect the switch plates or bars 81 and .84.A wire 122 runs from the switch bar 84 to the coil of a secondelectromagnet 123, and the other end of said coil is connected by a wire124.- to a finger 125 carried by the machine frame, preferablyad'ac'entto the finger 91. Said finger 125 ma es contact with a contactplate 126, carried by the table 1 adjacent to the plate 92, and a wire127 connects the plate 126 with the contact 26".

After the wheel dressing operation above described, and with theresumption of grinding upon the workpiece 7, the inward feeding of thegrinding wheel 5 involves further clockwise rotation of thering 18,which ultimately carries the cam 20 into engagement with the screw 22.The parts are so set and adjusted that the engagement of cam 20 withscrew 22 and the consequent rocking of lever 23 that carries screw 22,brings together the contacts 25 and 26 just as the workpiece 7 reachesthe exact desired size. This contacting completes the electrical circuitthrough the magijeaaeva net 123, since the contact 25 is rounded thesame as the contact 25, at 94. hus the electromagnet 123 is energized,causing attraction an armature member 128 pivoted on the same spindle 97which forms the pivot for the armature member 95, the magnet 123 beingdirectly behind the magnet 89. The armature 128 provides a lever arm 129for cooperation with the left hand table dog 77 in the following maner:

Said table dog 77,- as shown in Fig. 8, is pivoted at 130 to itscarrying block 106', and normally rests by gravity against a pin 131,

thereby to maintain its freeend in position to engage and move thereversing member 78 at the end of the right hand normal working strokeof the table 1. When the magnet 123 is energized, the lever arm 129 israised into the path of dog 77, and the latter, on the right handmovement of table 1, by reason of its pivotal mounting, is free to rideon the u per surface of said lever arm; thus the stri ing end of saiddog 77 is carried clear of the reversing member 78, and the table 1continues its movement to the right, carrying the grinding wheel 5 outof the workpiece and well past the then inoperative dressing device 9,said table ultimately carrying the grinding wheel 5 into the ositionillustrated in Fig. 8, and then being rouglit to a full stop by anysuitable means, as shown, for example, in said latter, at its rearPatent No. 1,582,468.

Referring now to the right hand side of Fi s. 6 and 10 and thecorrespondin parts of Fi s. 3 and 5, a casting 48 is suita 1y attached,as by a bolt 49, and the pivot bolt 36, to the table 1. This casting 48provides a 10m:- nal 50 which receives a short shaft 51. The end,carries a downwardly dependin arm 52, which is shown in more detail in li 7. The lower end of this arm is in the pat of a lug 53 carried b thebar'32, and when the final movement 0 separation between thegrinding'wheel and the workpiece occurs, the lug 53 and .arm 52 cometogether as shown in Fig. 7, the latter being rocked to the dotted linefposition of this figure. This rocks the sha t 51 in a clockwisedirection, on account of a key or pin 54 in said shaft, but when contactis made between lug 53 and arm 52 in a reverse direction of travel, asthe grinding wheel moves to enter a new workpiece, no movement of theshaft 51 is produced, since a slot 55 is provided in arm 52 to allowsaid arm to move in a counterclockwise direction of rotation withoutmovinv the pin or key 54.

i. uitably fastened at. the front end of shaft 51 is a member 56. Saidmember, of course, receives the clockwise rotation referred to, and aspring 57 returns the parts to the normal position, as shown in 6 and10, immediately after the operative engagement of member 52 and lug 53.The member 56 pivotally carries at 58 a pawl59. The latter contains aspring pressed lun r device 60 similar to the one already escri for awl38, and a stop lug 61 on member 56 olds the pawl 59 in the positionshown, until memwise fastened'to the sleeve 17.

Conveniently pivoted at 63 on the casting 48 is a member 64, having aplurality of pawl teeth 65. When the member 56 is in its normal positionof Figs. 6 and 10, a locking plate 66 carried by it engages a bevelledsurface on the member 64 and, owing to the leverage effect obtained bythe shortness of distance of plate 66 from the pivotal'center of member56 and the inclined plane action, the teeth are firmly held a ainstratchet 62 by the pressure of spring 5 Also the above acts as a stopdevice to hold the parts 51, 52, 56, etc., normally in the positionshown. Of course, when the member 56 moves inwardly, the plate 66, beingattached to it, moves away from member 64, and thus the lock isreleased.

Between the ratchet wheel 12 and the ratchet wheel 62 is a groove 67 inone of said ratchets, and an irregular but generally circular wire 68 isinserted in said wire 68 is constrained to lie in a plane, and thereacting pressure of the latter acts as a brake on ratchet 12. Thisrevents any retrograde motion of said rate at from any cause, such asthe dragging efiect of the pawl 38.

Assuming now that an unground work piece has been secured in the chuck 8all necessary adjustments made and the mac ine set in operation; therotating and reciprocating grinding wheel 5 gradually enlarges the holein workpiece 7 as, at each stroke of said wheel 5 caused by thereciprocations of table 1, the cam member 33 lifts the roller 34 withthe resultant movement of the cross slide 2' on table 1. The indingcontinues uninterruptedly until, y the continued movement of ratchet 12and consequent rotation of the annular piece 11 and ring 18, the camprojection 20 on said ringen a es the. screw 21, thus moving the firstroc ever 23 and bringing the first set of terminals 25 and 26 together.This closes an electric circuit and,

groove.' Thus the .ber 56 is moved inwardly. When this 70 Ill by meansalready fully described, causes the wheel 5 to be dressed and trued.

Subsequent to the dressing stroke first described, the grinding is againresumed, and

after a determinate number of reci'procationa lationship between thehand wheel 11 and the solute motions will now be explained, it being thechuck 8. As said table 1 moves outwardly, the depending arm 52 strikesthe lug 53 on bar 32 an thus the arm 52 is moved as described, whichcauses the lock 57 to be released, and the pawl 59 to move the ratchetwheel 62 in a clockwise direction.

This automatic movement of the ratchet 62 produces the compensation inthe following manner :'-When ratchet 62 is turned slightly clockwise,sleeve 17 and gear 17 to which said ratchet is fastened, must likewiseturn. This causes a change in the geared rethe finish of the grindingoperation, moves cam 20 on ring 18 a given angular distance beyond thecontact position of thumb screw 22, shaft 10 being turned an equalangular distance. When, therefore, in repositioning the cross slide 2 sothat the wheel 5 can enter a fresh workpiece, the operator has turnedthe hand wheel 11 far enough in a counterclockwise direction to bringthe cam 20 to that position where it had just previously causedautomatic cessation of grinding by contact with screw 22, the parts 11,11, 12, 18 and 20 are in the osition they occu ied as the wheel 5 leftthe ast workpiece. nd such re osiscrew shaft 10. For, inasmuch as thegrindtionin has turned the shaft counterc ocking machine of theinvention is intended for wise, but only bya limited amount. Suchprecision work, it is not necessary, in between/ limited amount is onlya small fraction of the ready access to the grinding of workpieces, toretract the previous automatic turning, said fraction becross slide 2 bya. greater amount than i 'ing, of course, the same as the fractionreprere resented by a partial rotation of the hand sented by thereducing action of gearing 1e, w eel. Consequently, so long as thesleeve 15, 16 and 17. 17 and gear 17 remain stationary, each angu- Theresultant of the above is that the cross lar position of the hand wheel11 and, conse slide 2 is automatically advanced in relation quently ofthe cam 20 represents a different to the hand wheel 11, ring 18 and cam20 by but definite angular position of the screw an amount representedby the given angular shaft 10. This is because the gear 15, whichdisplacement of ratchet 68 minus the fracis integrally united to thegear 14, as already tional return motion. This compensates forexplained, moves on the gear 17 when said the reduction of wheel 5 bygrindin and by gear is stationary, as on a track. Movement, dressing,the fixed redetermined a vance of then, of this gear 17 produces a newrelationthe grinding wheel yond the dressing plane ship between the handwheel 11 (and consebeing relied on to accurately and automaticalquentlalso the cam 20) and the screw shaft ly bring the workpiece to a givensize. 10, an the gear ratios are such (gear 14 being Of course, thiscompensation should be adsmaller than gear 15) that, relativelyspeakjustable in amount, and to this end, a shield ing, the screw shaft10 is moved forward in member 70 is provided for the pawl 59, saidrelationship to the hand wheel 11 and cam 20. shield being adjustable asby a screw and slot The gearing 14, 15, 16 and 17 in fact con- 71, 72.stitutes a differential mechanism, from the fact that the axis of ears14 and 15 is movable with the hand w eel 11, said axis bein representedby the stud 13. Thus it wil be seen that movement of the elementcomrising the parts 12, 11, 11 and 13 results in ceding movement of theshaft 10, and movement of the element comprising parts 62, 17 and 17results also in feedin movement of the shaft 10, the first feed beingthe normal feed and the last named a compensating feed. In the abovedescription, the motions described are relative motions. To make theoperation of the parts entirely clear, the ab ary iece 73 is provided,having a mark 74 whic by cooperation with the scale markings on ring 18,indicates to the operator the stage of grinding. Usually the zero markon the scale is set to come opposite the mark 74 when cam makes thefinal circuit by moving screw 22. Desirably also, the rin 18 carriesanother cam member 75 which, y engagement with the pin 43, automaticallyreduces the amount of feed, but this is no part of my invention.

Having described the actual as well as the relative motion that occursduring the compensation, it will be apparent to all those skilled in theart that many reversals of parts and motions could be made. For example,instead of compensating by changing the setting of the gearing betweenthe cam 20 and the screw shaft 10, the contact screws 21 and 22 could bemoved directly. For in my invention, the distance between either contactscrew and the cam 20 is a function of the position of the screw shaft10; that is to say, each separate angular position of the shaft 10,between successive compensations, deter mines a given distance between,for example.

understood that this explanation is given only as illustrative of oneway in which the mechanism operates, since the absolute motions would bevaried by a change of friction of the parts, or by placin a differentload on the machine. As actua ly observed, all the crossfeed partsrotate together during the 0mm pensating movement. Thus the hand wheel11 and the parts thereto attached, such as the drive ratchet 2, also thesleeve 16 and the screw shaft 10- tself, all'rotate clockwise for alimited distance. This action, occurring at Desirably also, a suitablerelatively station- Y Ill the screw 22 and the cam 20; and this wouldstill be true of the mechanism modified as above suggested. Thecompensation, in effeet then, alters the value of that function.Similarly, by a simple change in the mechanism illustrated in Figs. 5and 6 the automatic compensation could be made to occur when the table 1is moving inwardly to'carry the grinding wheel 5 into workpiece 7 v atthe commencement of the grinding operation instead of operating, as itdoes, when the table runs outwardly at the finish of a grindingoperation. This chan' e would in no manner alter the function or timachine and in fact the identical parts could be used some of thembeingarranged in re verse relation to some other parts, and therefore, in theappended claims, the phrase extended movement turn as well as theoutgoing movement of the table 1 and the short extended movement as wellas the long extended movement, except where the terms of a claim itselfre uires a different construction. These modifications above, andsimilar ones, being clearly within the concept of my inventionfallwithin the spirit of the'appended claims.

I claim: v

1. In mechanism of the class described, a transverse feeding element, adriving member therefor, gearing connecting said feeding element to saiddriving member, automatic means for progressively advancing said driving member, a table mounted for movement on a machine frame providingfor a traverse betweenthe work and tool and an extended movement, andmeans responsive to extended movement of said table for changin thesetting of the gearing connecting sai feeding element to said drivingmember.

2. In mechanism of the class described, a transverse feeding element, adriving member therefor, gearing connecting said feeding element to saiddriving member, automatic means for progresslvely advancing said drivingmember, a table-mounted for movement on a machineframe providing for atraverse between the work and tool and an extended movement, and meansresponsive to said extended movement of the table for autmaticallyprocuring a change in the setting of the caring between saidfeeding'element and its driving member.

In mechanism of the class described, a transverse feeding element, adriving member therefor, gearing connecting said feeding element to saiddriving member, automatic means for progressively advancing said drivingmember, a table mounted for movement on a machine frame providing for atraverse between the work and tool and an extended movement, and meansresponsive to said extended movement of the table for automaticallypredetermining angular dise mode of operation of the p or words ofsimilar import are to be construed as covering the reber'thereforrotatable in opposite directions to secure, respectively, feeding andwithdrawal movements of said fcedin g element, a

table mounted for movement on a machine frame providing for atraverse-between the work and tool and an extended movement, a secondmember rotatable with said feeding element, means set in operation bysaid seeond member on its arrival at a predetermined point to procuresaid extended movement, and means responsive to said extended move mentfor automatically causing a movement of said feeding element independentof actuation by said driving member.

5. In mechanism of the class described, a transverse'feeding element, adriving member therefor rotatable in opposite directions to secure,respectively, feeding and withdrawal movements of said feeding element,a table mounted-for movement on a machine frame providing for a traversebetween the work and tool and an extended movement,

a second member rotatable with said driving member, means set inoperation b said second member on its arrival at'a prer eter'mincd pointto procure said extended movement, and means responsive to said extendedmovement for automatically predeterminin an angular displacement betweensaid fee ing element and said second member.

6. In mechanism of the class described, a transverse feeding element, adriving member therefor, automatic means for progressively' advancingsaid driving member, a table mounted for movement on a machine frameproviding for a traverse between the work and tool and an extendedmovement, a second member advanceable' with said driving member meansset in operation by said second member'on its arrival at apredeterminedpoint to procure said extended movement, and means responsive to saidextended movement for automatically causing a movement of said secondmember independent of the automatic means for progressively advancingsaid driving member.

. 7 In a cross-feed mechanism, a transverse feeding element, adifferential gearing for actuating it, one end gear of said differentialrotatable for normal feeding movements and the other end gear adjustablefor compensating feeding movements.

8. In mechanism of the class described, a

transverse feeding element, adriving member therefor, means to give saiddriving member a progressive automatic advancement, a normallystationary element, means for periodically moving said normallystationary element, and a.

differential gear train, one end thereof being connected to said feedingelement, the other end being connected to said normally stationaryelement, and said driving element being intermediately connected to saiddifferential.

9. In mechanism of the class described, a feed screw shaft, a drivingmember therefor, means to-give said driving member a progressiveautomatic advancement, a pair of rigidly attached gears carried by saiddriving member, a gear connected to said feeding said driving member, atable mounted for movement on a machine frame, providin for a traversebetween the work and tool and an extended movement, and means forproducing successive changes in the setting of the gearing between saidfeeding element and its driving member, responsive to successiveextended movements of said table.

11. In a compensating mechanism for the transverse feed for grindingmachines, a table mounted for movement on a machine frame, providing fora traverse between the work and tool and an extended movement, atransverse feeding element, a pair of members one of which is movabletowards the other simultaneously with the advancing action of the saidtransverse feeding element, mechanism brought into operation by thebringing together of said pair of members for giving said table saidextended movement, a ratchet gear, means responsive to movement of saidratchet gear adapted to change the relative position between two ofthree members, viz, the transverse feeding element and the pair ofmembers, means respon sive to said extended movement of said table formoving said ratchet gear through a predetermined angular displacement,and means of which is movable towards the other simultaneously with theadvancing action of the said transverse feeding element, mechanismbrought into operation b the bringing together of said pair of membersfor giving said table said extended movement, a ratchet gear,

means responsive to movement of said ratchet gear adapted to change therelative position of two of three members, viz, the transverse feedingelement and the pair of members, a lock mechanism normally holding saidratchet stationary, and automatic means responsive to movement of saidtable for releasing said lock.

13. In a compensating mechanism for the transverse feed for grindingmachines, a

table mounted for movement on a machine frame, providing for a traversebetween the work and tool and an extended movement, a transverse feedinelement, a pair of members one of whicn is movable towards the othersimultaneously with the advancing action of the said transverse feedingelement, mechanism brought into operation by the bringing together ofsaid pair of members for giving said table said extended movement, aratchet gear, means responsive to movement of said ratchet gear adaptedto change the relative position between two of three members, viz, thetransverse feeding element and the pair of members, a lock mechanismnormally holding said ratchet station ary, and automatic meansresponsive to movement of said table for releasing said loci: and movingsaid ratchet through a predetermined angular displacement.

Dated this eleventh day of January. 1920 EDIVARD M. TAYLOR.

